docs: add field descriptions to the settings schemas

Document all 70 configuration fields with pydantic Field
descriptions, ported from the config sample comments and verified
against the actual consumers (allow_remote_console and local had
no documentation anywhere). The descriptions flow into the
OpenAPI schema of GET /v3/settings, giving the Web UI tooltips,
defaults and validation bounds from a single source. Response
models re-declare six path fields as plain strings, which drops
the inherited description — restore them explicitly.

Sync the config sample: document local and allow_remote_console,
drop hardware_virtualization_check which no longer exists in the
schema.

gns3server/config_samples/gns3_server.conf

@@ -16,6 +16,9 @@ default_admin_password = admin
 
 [Server]
 
+; Local server mode, set by the --local command line argument (not meant to be set by hand)
+;local = False
+
 ; Server name, default is what is returned by socket.gethostname()
 name = GNS3_Server
 
@@ -77,6 +80,10 @@ console_start_port_range = 5000
 ; Last console port of the range allocated to devices
 console_end_port_range = 10000
 
+; Allow console connections from remote machines
+; (console ports only accept local connections by default)
+;allow_remote_console = False
+
 ; First VNC console port of the range allocated to devices.
 ; The value MUST BE >= 5900 and <= 65535
 vnc_console_start_port_range = 5900
@@ -135,9 +142,6 @@ install_builtin_appliances = True
 ; Automatically pull updates from the skills repository when reloading
 ; skills_auto_update = false
 
-; check if hardware virtualization is used by other emulators (KVM, VMware or VirtualBox)
-hardware_virtualization_check = True
-
 [VPCS]
 ; VPCS executable location, default: search in PATH
 ;vpcs_path = vpcs